Replace Guest user with a Azure AD user

[VigneshGanesan]

Hi All,

   I'm currently working on a Tenant-to-tenant migration scenario and I'm looking for some suggestions, ideas or if possible a PowerShell script which can help me achieve this...

Company A has purchased Company B and now as a part of this M&A we need to migrate all the M365 workloads from Company B's tenant to Company A. Now ,in the past Company A and Company B used to work in close collaboration with each other and a result of that Company A users have invited a lot of users from Company B as a guest . So, is there a way to match a guest user from Company B to his corresponding migrated Azure AD user account in Company A and replace all the existing memberships with the new Azure AD user account ? 

We want to ensure that the group membership and all the other different memberships which the guest user had in the past gets replaced with his corresponding new Azure AD user account in the target . So, to put in simple words is there a way to replace a guest user account with a new Azure AD user account  and ensure that all the existing memberships remains intact. If yes, how can that be achieved? 

[#2]

Never heard of anything like that, so not sure it's even possible. AFAIK no. But I don't work with migrations/infra either. For multi-tenant scenarios it's common to have the UserType as Member (external member) when they need member-level access to resources in the organization’s other tenants. But that presumes it's still multi-tenant.